class_docstr: Index subclass for indexes backed by ExtensionArray.
class_docstr_tok: ["Index","subclass","for","indexes","backed","by","ExtensionArray","."]
code: def _isnan(self) -> npt.NDArray[np.bool_]:
      # error: Incompatible return value type (got "ExtensionArray", expected
      # "ndarray")
      return self._data.isna()
  
file_path: catboost/contrib/python/pandas/py3/pandas/core/indexes/extension.py
imports: from __future__ import annotations
  from typing import TYPE_CHECKING, Callable, TypeVar
  import numpy
  from pandas._typing import ArrayLike, npt
  from pandas.util._decorators import cache_readonly, doc
  from pandas.core.dtypes.generic import ABCDataFrame
  from pandas.core.indexes.base import Index
label_desc: Use image node_id 3 for calling the ExtensionIndex obj's underlying member method code with example usage: obj._isnan() and returns: self